CYMA M4A1 Full Metal Carbine AEG Gel Blaster

Righto, commitment time!
So on the weekend I bought one of these.

I will start with an initial review, and then move to what I do best through the coming weeks and play with it’s insides.

In the box:
The blaster
Metal cyma STANAG mag
outer barrel entension
gel bottle
cheap safety glasses
gold packet milky looking gels
plastic barrel cleaning rod

The barrel cleaning rod was an awesome surprise for me, it is something that we should have given the amount of ultra hard gels I have seen jammed in broken blasters in the past couple years. Don’t clear your jam with your trigger finger kids!

No battery or charger here. And honestly, that is not a bad thing. Included “free” batteries and chargers are garbage anyway, and both are things I recommend getting a proper balance charger, and decent quality batteries that suit you application, not a generic free inclusion.

Externally:
Awesome. Very little play and movement in the blaster. It is all metal except the A2 pistol grip and crane stock. Cyma’s crane stocks are great for fitting larger Titan nunchuck batteries, allowing for more capacity without external mounting of batteries, so you can keep the replica look; something I value highly. You could also store three smaller lipo batteries and just remove the rear pad to swap connectors. It is nice to have options. Aesthetically the stock is something I like anyway so this is win win.

The standard A2 pistol grip does not appeal to all people, but it does to me as they are great at motor/pinion alignment. Almost like the system was originally designed by Tokyo Mauri way back when using an A2 grip. Also for the aesthetics of this replica, is suited well.

The barrel is very secure, as is the RIS handguard. The sights are nice, and rear CQB model sight is good for mounting a red dot style sight and still retaining the iron sights. Again nice to have options. Something does trigger me about having the front triangle sight with not partner on the rear if mounting an optic by removing the carry handle, again just a nice to have. I may get a full carry handle yet.

The flash hider can be removed with a small grub screw then standard 14mm ccw thread off. There is also a barrel extension, for those wanting a standard length M4A1 rather than a CQB, or in my case those wanting to mount an M203!

The standard inner barrel is 285mm long, with a step down that fits into the flash hider in CQB configuration. Sadly, you can not fit any style of hopup with the standard flash hider. The muzzle itself is tapered inside and too small to fit anything in, and the extension is just too tight to fit a sweetheart style hopup into. Unfortunately, this means I am going to have a different flash hider just to get a hopup, though I may still explore modification to the barrel extension for fitting a sweetheart hopup as it is almost large enough. We will cross that bridge in the build.

And of course, my short M203 is already on there.

Initial performance:
I had mixed feelings with straight out of the box performance, some of that is my fault, and some the manufactures. The only gels I had to try ready at the time were either old Ultra Elites, or old Predator v2s. Two months old actually. Knowing what happens with old elites in AEGs I opted for the safe option of the smaller predators. Gave them a quick “moistening”, in the mag and off I went. A couple of gels down range in the garage and it stopped firing.

“F*****g cyma mags already!” I thought… pop the mag out and there in the feed tube was some shrivelled up old dried out milky white gels. I opened the mag, and there were quite a few. Disappointing, especially as someone who has worked in the retail/tech side I know this would lead to an annoyed customer interaction on the phone then in the store. Also have I voided my warranty by opening the mag? Yes. I don’t care, but a newer less experienced customer would! Anyway…

Once the mag was dealt with it fired fine. Very standard performance for a $400 blaster. Averaging 280fps, exactly what X-force’s page says they got with the Predator V2 gels.

I didn’t get a photo with the full size Ultra Elite gels, but they were closer to 300fps average, and the old Ultra Elites did indeed jam a few times as I expected, but anyway… it isn’t like I wasn’t expecting that!

The blaster actually sounds like the motor height is set well and the shimming sounds bob on. I will verify this when I open it up, but it looks like CYMA has stepped up it’s game here.

COMING UP:
You all know I am getting inside this thing and further voiding my warranty :wink:

Experienced tinkerers know, you don’t get a CYMA metal gearbox blaster for how it performs in stock form. You get it for what it can become with a few parts!
I haven’t been inside a CYMA metal gearbox from this recent import batch, but we will get to that.

I have had the upper off already to eyeball the cylinder porting and yes, it is about a 70% port, which is fine for the barrel length. It is better if the seals are good, which judging by the chrono it is a little lacking there. I will be swapping to a full cylinder, and getting a barrel around 380mm to suit the extension.

If previous is anything to go by, o-ring will be needing a replacement, and the nozzle will not have a perfect seal. The gears used to be a typical “cast gear lottery”. Some would handle a faster motor, 11v and an m100, and the odd one would strip in stock form. Cyma pistons are pretty tough, built plenty with an m110 and close to 30rps with the stock piston.

Though the piston heads are REALLY on there, and the piston head is usually what I want to change, and since some just don’t come off, I usually ended up just replacing the piston as well, time is money as much as parts are here.

The standard motors were weak. Seriously weak. Just using an m100 will see a dramatic drop in rps, so this is going to go for me.

Generally, gears, piston and head, cylinder head and nozzle, spring and motor and these gearboxes are happy to over 30rps and close to 400fps.

MY BUILD PREFACE
The limitation for my build is going to be it needs a full stroke and cylinder with the longer barrel, so I won’t be going over 30rps on 11v. I also will be trying to keep it closer to "most field limits: of around 330fps, which will also help with some accuracy.
What I am actually going to be chasing is an efficient build, hoping to run an “army” stock with a normal size lipo, and get a lot of shots out of a smaller battery. Again, aesthetics are important on this one.

The one exception to this is going to be mags. I run SLR mags, so there will be some faffing to get them fitting nicely and feeding well. I will be designing and 3d printing an bit of an adaptor this time. Previously I would just change to LDT nozzle and tpiece, but this time I want to if my patience allows get the adaptor tube working.

It will have a snappy semi, and close to 11v rps a 7v battery, but with the option to be a little naughty on 11v if I feel like it. Reliable efficient consistent performance with decent accuracy is the name of this ones game. I am still deciding on how to do this, but I am thinking a warhead motor may be involved. I currently don’t have a good motor spare, so I am up for buying a motor, or changing the armature in another neo can to suit.

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Excellent review, nicely done @RokSolid :+1: Very handy for anyone considering buying one of these.

Great to hear your keeping the aesthetics as a proirity, it always been mine with all of my builds.

I totally agree with your assessment of the CYMA motors… those and the mags are definitely the weakest links, but pretty easy to upgrade both. I’m keen to see the results of your modifications, so keep us updated. It’s going to be invaluable stuff for a lot of the new members in here.

Like bringing back the biffo in NRL, I say bring back the mods! There hasn’t been much modding content lately, probably because standard blasters are light years ahead of the old Gen8s and early V2 blasters… and it’s all too easy to think that everyone on the forum’s an old salt with years of experience. Plenty of newbies would get a lot out of posts like this one. :+1:

Yes @Friendly_Fire it’s been a while… last one I published was the mk vector, but I have done plenty since then I am just lazy.

It is certainly hard for me to remember that everyone starts somewhere and doesn’t know a lot. I have learnt enough to know you can’t know everything, I am not the best by a long shot but pretty good at everything.
I don’t believe in rinse and repeat for my stuff and I’m always looking for better ways of doing things. For customers I do like to keep things in the comfort zone as reliablility is key for them!

Anyway… let’s crack on!
This is the stock I love for hiding good size battery.


Bye warranty!



Why is the wiring so long! And the fuse… I get why they are there on one hand. But for me I know to just stop pulling the trigger if something goes wrong.
It has a deans plug and no fuse now, an I guess with all the extra wiring I didn’t have to replace the fuse with a length of wire so still good.

Now here is interesting. And a bit frustrating as it was so close to being truly awesome.


You can access but can’t remove the spring. I could grind the receiver to allow it I spose… but I wish it came with this spring retainer…

I will try and order one… and the twist off style cyma buffer tube too. It will have to come from overseas so I will revisit that if and when it makes it here.
But it would allow you to twist the buffer tube off, unscrew the spring retainer which is held very straight, change spring and reassemble. If it had that would be perfect. Certainly not a deal breaker but I think we deserve it haha.




Forgot to add these in the last post.
The drop in size on the end of the barrel that fits in the flash hider. Works but no good for those of us wanting a hopup.

Also the screws have some sort of goop in them. It’s not thread lock as they still come out easy enough but might be for a bit of piece of mind to help stop screws backing themselves out with all the vibration. Good idea, not sure if it works though.

Yeap, standard cyma 480 motor. Press fit d type. They are good for helping the blaster last through warranty since there is not slot of speed or torque.



The redish colour on the motor plate seems to be a lube not rust. It’s also the nice type not that stupid grub screw and disc style.
Motor height screw is very… very tight. Probably some sort of glue or thread lock there.

Worth noting, this particular gearbox the shimming is Bob on. Moves freely, but has almost no lateral movement on the shafts. Well done cyma.

Mag release is a torx head. Just to make sure the beginners aren’t easily getting into them I guess. But better than a rounded out hex.

There is a plastic locating shroud thing at the back. It will stop the box coming out easily, dampen some vibration and centre the gearbox.


Slide it forward…

Don’t forget to remove the bolt release by punching out the pin

Rotate it out…

And then with some fun jiggling the captive rear pin and gearbox it is free!

I have begun my tpiece adaptor… Still in test fitting stage, it enters the SLR and gen8 mags nicely (gigidy) but still needs to be a bit tighter as I am going for a press on fit.
I will then add a plate to contact the gel ball stopper button on the mags also, probably attach with a slot in and lock in style to make printing easier so I don’t have to faf around with supports.



Ldt tpiece for reference. Not a bad tpiece but they aren’t perfect for feeding. You can just use an ldt nozzle and tpiece, then add some material to the gearbox to contact the gel ball stopper button, in the past I have printed a terminal plate that does that but it removes the mag prime function.

And yes, if anyone wants the final product just ask. Anything to get all my m4 range on the same SLR and gen8 style right.

I replace mine with a countersunk hex head… just because I’m too lazy to hunt up a torx driver. :joy:

Multiple fastener types do my head in. :rofl:


There it is. Standard metal cyma gearbox affair. No air seal on the piston. The nozzle was actually very tight… but I already had this full stainless cylinder with a cyma head and nozzle ready, so swapped for that and a green o-ring.

The pistons in these are tough, beware if you do aoe correction though as they are a full toothed rack. Even with the new cylinder head it is very close to picking up a tooth early.

For now, good seals and full cylinder is all I am doing. No point building it out until my motor comes.

For those with a keen eye, cyma sector gear only has 14 teeth, not the full stroke 16 teeth. That will change next time when I do gears.

The old tpiece in boiling water trick loosened the glue enough to get the barrel out, no has a 400mm 7.5mm id barrel.

A quick run on the chrono reveals its under volumed as expected, fps spread is better but still showing signs it needs a bit more air. Average of 300-310 fps, just like any cyma with a metal box and long barrel really.

After this test I found the mag is very prone to jams. More reason to push on with the adaptor. My printers memory card or my card reader just ate it though so that might have to wait till tomorrow :face_with_symbols_over_mouth:

@Friendly_Fire yes the multiple screw drivers needed is a pain. Apart from the one torx screw 95% is the one Philips head.

So it happened… I started the journey.
The warhead base 27k I received yesterday immediately had the pinion loctited on.
Then this morning disassembled it, removed everything from the gearbox and gave it a quick clean.
Then came choose a piston and head and get it loctited on. Realistically now I should wait for tomorrow to fire it, but there is plenty of work to do before that is a possibility anyway.


Motor height set. Gears all shimmed, I am now at the stage where I will give things a proper clean, and getting things reinstalled and lubed up.

I will be trimming the tappet plate, and likely using a stronger return spring. This shouldn’t be mental rate of fire, actually hoping on a 7.4v it is close to realistic max rpm of an m4, so around 950rpm or 16rps. I won’t complain if it is a bit more, my HL honey badger with CNC box and warhead 30k does about 18rps on 7.4v so I reckon it will be right where I want it.

And the 11.1v rate of fire will be a bit naughty at 24rps, but still safe for a long barrel and full stroke. Going for efficiency and reliability over all here.

There will be no ETU here, as the semi trigger feel of cymas is pretty nice when the are a bit quicker, again, keeping it a bit milsimy.

Those with a keen eye will note the non warhead motor tower on the warhead. Warhead towers are 9.0mm, and the red one is 9.5mm. fits much better in the grip and gearbox with far less movement.

While shimming I noticed one of the bushes click in the gearbox a bit deeper… seated them all the way, now that stock beautiful shimming is looking more like they just put shims and bushes on the gears and screwed the gearbox closed.

It worked for cyma granted, that lovely shimmed gearbox would definitely not have stayed that way though. There is good reason I open every blaster and go over things. Because china quality.


I have a few prototypes of the tpiece adaptor and gel ball stopper button shim to try out. Discovered the feed tube and buttons are different between SLR mags and gen8, so I will be looking for a design that suits both.

It is designed to be printed with no supports, and the piece that goes under the gearbox to push the stopper button clips on very tight. The one I did try broke off, which is good and by design. This way it can be installed easily and pressed into the gearbox and stay there, while allowing the barrel to be removed separately.
Also printing both parts in the one model is convenient.
Further testing of that will have to wait until the rest is built.

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Sounds like you’re all over that like white on rice… :wink: cheers for that great build update. :+1:

I’m a big CYMA fan, and I’ve always just run the metal gearboxes stock, but reading your posts makes me want to go nuts on my XM build. :rofl:

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I love a cyma. The are pretty predictable for mods, have a few quirks but what doesn’t.
They are good stock really, no need to go nuts, I just have a problem!

It’s back together, I pulled the trigger on semi twice to verify it works… it does! I am going to wait until tomorrow when the Loctite is cured though on the pinion and piston head.

It isn’t pretty and I went a bit overboard with moly grease, but if all goes to plan it will not be open for a long time.

The return spring is actually very strong, stronger than I remember but it has been a while since I’ve been in a stock cyma metal box. Most in the wild have been owned for quite a while and had them replaced. I coated it in grease to help it stay rust free, a trick that has seen a few of my blasters run the same return spring for years.

Only slight tappet trim, it’s not going to be stupid fast.
I also gave the trigger contacts a thorough cleanup with alcohol as that is a cyma thing.

Now we wait till tomorrow to see if the printed parts get it feeding on the SLR or gen8 mags, my guess is there will be a few more iterations on that piece yet, but here’s hoping!

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Give it a run. Hopefully this m100 calms down a little, was pushing 370-400fps! 400mm barrel does give an fps bonus but, it will bed in and settle down.

It runs, exactly as expected rof wise. I had calculated that it would be around 950rpm on 7.4v, similar to the top end of a real M4. And it comes in at 940rpm. 16rps. So it is almost as fast as a standard blaster on 11.1v, but on 7.4v.

Which leaves it running at 1400rpm/23rps on 11.1v. A bit quicker than a normal blaster but not very impressive. Also seems very slow to me (considering most of my builds are around 25+rps.

And then it sounded odd. Didn’t get far into opening up and discovered the pinion on the warhead 27k was pushed down. I was able to slide it off with force, but obviously wasn’t quite “on there”. Cleaned, reapplied red loctite, and then sent the poor little grub screw to hell.

Then I got to thinking, I will pull the 30k warhead out of my honey badger and try it. Only a handful of shots off, and boom. Broke a motor tab off. Tried to solder it back on, but it has been done half a dozen times now and it refuses to stay soldered on. Time for a new esc.

Anyway, got some data, fitted a hopup, wait a few days to make sure the pinion loctite cures. Try to find someone with a new warhead esc. Joys.

EDIT****
Something I forgot to mention. My tpiece/gel stopper button pusher thing is a success. Works with both gen8 and SLR mags! While it does work, I noticed the stock black tpiece has less girth than the orange ones which are more common, so will have to adapt that.
Also going to refine it a little more but for now very happy with the results.

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